<!DOCTYPE html>
<html>
<head>
    <title>My App</title>
</head>
<body>
    <h1>Welcome to My App</h1>
    <p><a href="{% url 'myapp:hello_world' %}">Home</a></p>
    <p><a href="{% url 'myapp:sum' 5 10 %}">Sum of 5 and 10</a></p>
    <p><a href="{% url 'myapp:post' 123 %}">View Post 123</a></p>
</body>
</html>